Playability:
Back in the days... I used to spend all my spare time playing it, and I mean ALL. It has soaked up months of my time playing it over the years. But compared to todays games the gameplay is somewhat more repetitive, but its still worth a blast even now.

Durability:
There are several special missions available as you gain combat ranking, some triggered by your ranking, and some by visiting a particular planet. This helps to keep interest, as these offer some ship upgrades not otherwise available. But once you've completed the few missions, there is little to maintain that long term interest needed to gain your legendary Elite combat ranking.

Originality:
Its a genre producing classic, I cant really say if its exactly the first game to do it, but it seems that way to me. While the spaceships and aliens stuff isn't anything new of course, the way its all put together is what makes it its own gaming sub genre now. There have been several attempts to update the Elite game theme over the years, but none of them have had for me the shear playability of this originator.

Addictiveness:
Lets be honest, its a drug. When I think about it now, I feel what I think religious zealots must feel, like a religious fervour. Whenever I play my blue_danube.mid it brings me over all misty eyed, even though that is actually from Frontier ;\